摘要：contentprivoder好像自己没有遇到过，不过通常使用 联系人，日历等等之类系统自身提供的。简略的摘抄一下网上各位的资料以作为自己记录。对 其中 getType(Uri uri)方法还是不知道具体使用方法，暂且留在这里。等后面看能不能搜集到具体使用
//UriMatcher.NO_MATCH，是一个常量，如果不匹配就返回 -1
UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH); /**
*authority：就是 contentprivoder 的authority参数，这参数必须与 androidmanifest.xml中对应privoder的authorities值一样
*path：就是完整uri中，authority后的一长串
*code：对应码
*/
//addURI 添加一个 uri，如果这个 uri匹配成功则返回匹配吗，不匹配则返回 -1
public void addURI(String authority, String path, int code)//从以创建的uri树中去匹配传进来的uri，如果匹配成功，则返回匹配码，否则-1
public int match(Uri uri) public static long parseId(Uri contentUri) public static Uri withAppendedId(Uri contentUri, long id) private static final String AUTHORITY = "com.smaple.hu";
private static final int PEOPLE = 1;
private static final int PEOPLE_ID = 2;
private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH);
static {
sURIMatcher.addURI(AUTHORITY,"people",PEOPLE);
//这里的#代表匹配任意数字，另外还可以用*来匹配任意文本
sURIMatcher.addURI(AUTHORITY,"people/#",PEOPLE_ID);
}
private void testUriMatcher() {
Uri uriExact = Uri.parse("content://"+AUTHORITY+"/people");
Log.i("info","uriExact: = "+uriExact) ;
Log.i("info","match excat = "+getType(uriExact));
Uri uriNumber = Uri.parse("content://"+AUTHORITY+"/people"+"/2");
Log.i("info","uriNumber: = "+uriNumber) ;
Log.i("info","match number = "+getType(uriNumber));
//拼接Uri
Uri newUri = ContentUris.withAppendedId(uriExact,15);
Log.i("info","newUri: = "+newUri) ;
//获取 ID
long id = ContentUris.parseId(newUri) ;
Log.i("info","ID = "+id);
Log.i("info","getPathSegments = "+newUri.getPathSegments());
}
private String getType(Uri uri){
int match = sURIMatcher.match(uri);
switch (match){
case PEOPLE:
return "vnd.android.cursor.dir/person";
case PEOPLE_ID:
return "vnd.android.cursor.item/person";
default:
return null;
}
}I/info: uriExact: = content://com.smaple.hu/people I/info: match excat = vnd.android.cursor.dir/person I/info: uriNumber: = content://com.smaple.hu/people/2 I/info: match number = vnd.android.cursor.item/person I/info: newUri: = content://com.smaple.hu/people/15 I/info: ID = 15 I/info: getPathSegments = [people, 15]??在UriMatcher的 math( )方法中有一个 uri.getPathSegments( )，大致的意思就是按“/”进行切分。和下面的参考资料有所差异 ??想要实现自己的 contentprovider，需要继承 “android.content.ContentProvider“ 抽象类，在继承之后必须覆写以下几个方法。
<provider
android:authorities="com.hu.smaple.provider"
android:name=".hu.provider.TestProvider"
android:exported="true"
/>public class TestSQLite extends SQLiteOpenHelper {
private static final String DB_NAME = "provider.db";
private static final int DB_VERSION = 1;
private final String TABLE_NAME= "providertable";
private final String COL_ID = "_id";
private final String COL_NAME = "name" ;
private final String COL_AGE = "age" ;
private final String COL_INFO = "info" ;
public TestSQLite(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String sql = "create table if not exists ["+TABLE_NAME+"] "+"("+COL_ID+" integer primary key autoincrement, "
+COL_NAME+" varchar, "
+COL_AGE+" integer, "
+COL_INFO+" text)" ;
Log.i("info","create table = "+sql) ;
db.execSQL(sql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("ALTER TABLE person ADD COLUMN other STRING");
}
}public class TestProvider extends ContentProvider {
private static final UriMatcher sUriMatcher ;
private static final int MATCHER_TABLE = 1;
private static final String AUTHORITY = "com.hu.smaple.provider" ;
private static final String TABLE_NAME = "providertable" ;
private static final Uri CONTENT_URI_PROVIDERTABLE = Uri.parse("content://"+AUTHORITY+"/"+TABLE_NAME);
private TestSQLite testSQLite ;
private static final String CONTENT_PROVIDER_TABLE = "com.hu.smaple.provider.type" ;
static {
sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
sUriMatcher.addURI(AUTHORITY,TABLE_NAME,MATCHER_TABLE);
}
@Override
public boolean onCreate() {
testSQLite = new TestSQLite(getContext());
return false;
}
@Nullable
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
Log.i("info","query uri = "+uri);
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
switch (sUriMatcher.match(uri)){
case MATCHER_TABLE:
//设置查询的表
queryBuilder.setTables(TABLE_NAME);
break;
default:
throw new IllegalArgumentException("Unknow URI: " +uri);
}
SQLiteDatabase db = testSQLite.getWritableDatabase();
Cursor c = queryBuilder.query(db,projection,selection,selectionArgs,null,null,sortOrder);
return c;
}
@Nullable
@Override
public String getType(Uri uri) {
Log.i("info","getType uri = "+uri);
return null;
}
@Nullable
@Override
public Uri insert(Uri uri, ContentValues values) {
Log.i("info","insert uri = "+uri);
String tableName = null ;
switch (sUriMatcher.match(uri)){
case MATCHER_TABLE:tableName = TABLE_NAME ;
break;
default:
throw new IllegalArgumentException("Unknown URI: "+uri);
}
SQLiteDatabase db = testSQLite.getWritableDatabase();
long rowId = db.insert(tableName,null,values);
Uri result = ContentUris.withAppendedId(uri,rowId);
notifyChange(result);
return result;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
Log.i("info","delete uri = "+uri);
String tableName = null ;;
switch (sUriMatcher.match(uri)){
case MATCHER_TABLE:
tableName = TABLE_NAME ;
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
SQLiteDatabase db = testSQLite.getWritableDatabase() ;
int count = db.delete(tableName,selection,selectionArgs);
// 更新数据时，通知其他ContentObserver
if(count > 0){
notifyChange(uri);
}
return count;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
Log.i("info","update uri = "+uri);
String tableName = null;
switch (sUriMatcher.match(uri)){
case MATCHER_TABLE:
tableName = TABLE_NAME ;
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
SQLiteDatabase db = testSQLite.getWritableDatabase();
int count = db.update(tableName,values,selection,selectionArgs);
if(count > 0 ){
notifyChange(uri);
}
return count;
}
private void notifyChange(Uri uri){
Context context = getContext() ;
if(context == null) return;
ContentResolver resolver = context.getContentResolver();
if(resolver == null) return;
resolver.notifyChange(uri,null);
}
}public class MainActivity extends AppCompatActivity {
private ListView listView ;
private static final String AUTHORITY = "com.hu.smaple.provider" ;
private static final String TABLENAME = "providertable";
private static final Uri CONTENT_URI_TABLE = Uri.parse(
"content://"+AUTHORITY+"/"+TABLENAME
);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
}
public void add(View view){
ArrayList<Person> persons = new ArrayList<Person>();
Person person = new Person("Ella"+System.currentTimeMillis(), 22, "lively girl insert other app");
ContentValues cv = new ContentValues();
cv.put("name",person.name);
cv.put("age",person.age);
cv.put("info",person.info);
Uri uri = this.getContentResolver().insert(CONTENT_URI_TABLE,cv);
Log.i("info ", "insert uri =" + uri);
}
public void update(View view){
Person person = new Person() ;
person.name = "Jane";
person.age = 30 ;
person.info = "updata form other app";
ContentValues cv =new ContentValues() ;
cv.put("name",person.name);
cv.put("age",person.age);
cv.put("info",person.info);
int count = this.getContentResolver().update(CONTENT_URI_TABLE,cv,"name = ?",new String[]{"Jane"});
Log.i("info ", "update count=" + count);
}
public void delete(View view) {
int count = this.getContentResolver().delete(CONTENT_URI_TABLE,"name = ?",new String[]{"Jane"});
Log.i("info ", "delete count=" + count);
}
public void query(View view){
List<Person> persons = new ArrayList<>();
Cursor c = getContentResolver().query(CONTENT_URI_TABLE,null,null,null,null);
if(c.getCount() > 0 && null != c){
while(c.moveToNext()){
Person person = new Person() ;
person._id = c.getInt(c.getColumnIndex("_id"));
person.name = c.getString(c.getColumnIndex("name"));
person.age = c.getInt(c.getColumnIndex("age"));
person.info = c.getString(c.getColumnIndex("info"));
persons.add(person);
}
}
ArrayList<Map<String,String>> list =
new ArrayList<>() ;
for (Person person : persons) {
HashMap<String,String> map = new HashMap<>() ;
map.put("name",person.name);
map.put("info", person.age + " years old, " + person.info);
list.add(map);
}
SimpleAdapter adapter = new SimpleAdapter(this, list, android.R.layout.simple_list_item_2,
new String[]{"name", "info"}, new int[]{android.R.id.text1, android.R.id.text2});
listView.setAdapter(adapter);
}
} Person person1 = new Person("Ella", 22, "lively girl");
Person person2 = new Person("Jenny", 22, "beautiful girl");
Person person3 = new Person("Jessica", 23, "sexy girl");
Person person4 = new Person("Kelly", 23, "hot baby");
Person person5 = new Person("Jane", 25, "a pretty woman");
<provider
android:authorities="com.hu.smaple.provider"
android:name=".hu.provider.TestProvider"
android:exported="true"
android:writePermission="com.hu.smaple.privoder.write"
/> <permission android:name="com.hu.smaple.privoder.write"
android:label="privoder permissin"
android:protectionLevel="normal"
/>
<application
...| 属性 | 含义 | 是否必须 |
| name | 自定义的权限名称，通常需要遵循 Android权限定义命名方案：*.permission.* | 是 |
| protectionLevel | 定义与权限相关的“风险级别”。必须是以下值之一，在确定是否授予权限时，系统可能采取不同的操作
|
是 |
| permissionGroup | 可以将权限放在一个组中，但对于自定期义权限，应该避免设置此属性。如果确实希望设置此属性，可能使用以下属性代替：android.permisson-group.SYSTEM_TOOLS | 否 |
| label | 可使用它对权限进行简短描述 | 否 |
| description | 使用它提供对权限用途和所保护对象的更有用的描述 | 否 |
| icon | 权限可以与资源目录以外的图标相关联 ( 比如@drawable/myicon) | 否 |
??进行一写入操作就错误，log出的错误为：
java.lang.SecurityException: Permission Denial: writing com.hu.smaple.hu.provider.TestProvider uri content://com.hu.smaple.provider/providertable from pid=10690, uid=10102 requires com.hu.smaple.write, or grantUriPermission()
??当我们Androidmanifest.xml中像申请系统权限一样的方式把 writepermission权限申请一下，就又能愉快的玩耍了
<uses-permission android:name="com.hu.smaple.privoder.write"/>??对于数据变化时候监听，打印log测试后我在一个app里面使用注册 ContentObserver 实现类后，只用在自身 app，数据变化的时候，才会调用 onChange( )方法。
??在使用ContentProvider时由于我们无法得知数据的实际来源和数据操作的复杂度，如可能是读磁盘甚至是读网络，亦或有比较耗时的计算，所以我们无法保障数据返回的时间。因此就有必要使用异步查询来将耗时操作切换至后台线程，并在执行完成后切回到UI线程。对于直接使用Thread/Runnable - Handler这种情况实际上考虑的事情非常多，最关键的是写出来不优雅，用起来难受。我们可以使用Loader/LoaderManager和AsyncQuery
原文：http://blog.csdn.net/guyuelin123/article/details/64441319